A MAJOR OUTBREAK OF NOCTILUCENT CLOUDS: Over the weekend, noctilucent clouds (NLCs) broke free of the Arctic Circle and spread across most of Europe. The blue clouds, made of frosted meteor smoke, were photographed south of Madrid, nearly breaking the all time record for low-latitude sightings. This means NLCs could soon be coming to you. Full story and observing tips @ Spaceweather.com.
Above: Night-shining (noctilucent) clouds over Paris on June 20, 2021. Credit: Bertrand Kulik. More: Noctilucent Cloud Photo Gallery.